Ballywillan (Ballywillin) Church is situated one mile from Portrush on the Ballywillan Road. The name Ballywillin translates to ' town of the Mill' and was also known as Mylton.

The church ruin you see today dates to around the 16th century and probably replaced or was renovated from an older church built on the site in the 14th century. This church in turn replaced the church of Portrush which existed approximately midway between Ramore headland and Crocknamac Street, there are no visible remains of this church which is known to have existed in the 12-13th century.

The old graveyard at Ballywillin is unusually large when compared to other churches of a similar period, it has several decorative crosses in differing styles which include Celtic.

The graveyard also has a direct link to the English crown, buried in one of the graves is Dorothea Ross who it is said to have been the illegitimate daughter of King James II of England, who along with his army spent some time in the district during the 1689/90 campaign in Ireland which ultimately led to his defeat at the hands of his son-in-law William III.